Mesoscale Discussion 1427
   NWS Storm Prediction Center Norman OK
   0135 PM CDT Tue Jun 24 2025

   Areas affected...parts of north central Colorado and ern Wyoming

   Concerning...Severe potential...Watch possible 

   Valid 241835Z - 242030Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Intensifying thunderstorm development is likely to
   commence along the eastern slopes of the Front Range and Laramie
   Mountains during the next few hours.  This probably will include a
   few supercells impacting the Greater Denver vicinity through 3-4 PM
   MDT.

   DISCUSSION...Downstream of slow moving mid-level troughing across
   parts of the Southwest and Great Basin, southeasterly low-level flow
   is maintaining seasonably moist boundary-layer air across the high
   plains into the eastern slopes of the Front Range and Laramie
   Mountains.  Beneath relatively warm mid-level air to the east of the
   higher terrain, associated low-level cloud cover is slowing
   destabilization to the east/northeast of the Laramies through the
   Cheyenne Ridge vicinity.  However, across the Front Range, near the
   Greater Denver vicinity, insolation is more rapidly eroding
   inhibition and beginning to increase mixed-layer CAPE in excess of
   1000 J/kg.

   With additional surface heating, Rapid Refresh forecast soundings
   suggest that thunderstorms may begin initiating along the eastern
   slopes of the higher terrain, particularly near the Denver area,
   within the next hour or two, before gradually increasing and
   intensifying through 21-22Z.  In the presence of moderate to strong
   southwesterly flow in the 500-300 mb layer, deep-layer shear appears
   more than sufficient to support supercells.  These may pose a risk
   for large hail, and at least some potential for brief tornadoes, as
   they attempt to propagate eastward off the higher terrain.

   Due to the warm mid-level environment near/just above 700 mb,
   stronger storms might be, at least initially, slow to propagate away
   from the higher terrain.

   ..Kerr/Hart.. 06/24/2025

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...BOU...CYS...RIW...

   LAT...LON   43260560 42470476 41370437 40330385 39230445 40240534
               41990558 43110642 43260560 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN